Pronóstico: Highest temperature in Seoul on July 3?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded at Incheon International Airport on 3 July 2026, measured in degrees Celsius. Polymarket prices this contract today with the "28°C" outcome commanding a 98% probability, while "27°C" sits at 85%, leaving the "YES" option for any other range effectively at 0% [1]. This on-chain pricing, settled in USDC on the Polygon network via conditional tokens, reflects a collective market view that the day will be hot but not extreme, aligning with historical patterns where July highs in Seoul typically hover between 25°C and 30°C [4].

Historical data frames this current probability as rational rather than speculative. July in South Korea is the peak of the monsoon season, with daily average highs closing near 30°C, yet intense, short-duration rainfalls often suppress peak temperatures to the upper 20s [3]. The market’s heavy weighting on 28°C mirrors the typical midday anchor of 27°C, acknowledging that while humidity can make it feel like over 34°C, the actual recorded temperature rarely breaches 30°C unless a prolonged heatwave occurs [3][4]. The 0% probability for other outcomes suggests traders see little chance of a record-breaking anomaly.

Traders should monitor the Korea Meteorological Administration’s short-range forecasts for any sudden shifts in cloud cover or precipitation timing, as these are the primary catalysts for temperature suppression [6]. Recent reports indicate that heat in Korea this summer is arriving earlier than last year, with temperatures rising two to three weeks ahead of schedule, which could introduce volatility if the monsoon rains delay [9]. Additionally, the scheduled Sinchon Water Gun Festival in late July is not a direct factor for 3 July, but the broader pattern of concentrated July rainfall means traders must watch for the 60–90 minute rain windows that frequently interrupt sunny spells [3][4]. The resolution source, Wunderground, will capture the peak temperature regardless of these brief interruptions, making the timing of the heaviest rain the critical dependency.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Pronóstico: Highest temperature in Seoul on July 3? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.